Doubts over a massive new nuclear plant in the United Kingdom have sparked debate over renewable alternatives -- including the possibility of importing solar thermal power from north Africa.

Analysts at The Energy Research Partnership (ERP), a think tank and advisory body, said solar thermal “would count” as one of a handful of firm low-carbon energy supplies capable of taking the place of a proposed nuclear plant whose future is now uncertain.

Following years of negotiations between the U.K. government and developer EDF Energy, the 3.2-gigawatt nuclear plant, Hinkley Point C, was about to get the final go-ahead last month. But officials pulled back at the last minute, announcing a further review lasting until early autumn.

According to press reports, the government is now looking for ways to shut down the project in an artful way.

The Hinkley Point C project, largely crafted under the stewardship of the pre-Brexit government led by David Cameron, has attracted significant criticism for its cost.

Most of the GBP £18 billion (USD $24 billion) capital cost of the plant would be borne by EDF and its Chinese project partner, China General Nuclear Power Corporation. But the deal brokered by Cameron’s team would lock consumers into overly high power prices, critics say.

The plant would be entitled to sell electricity at £92.50 ($122.18) per megawatt-hour for 35 years. That is around twice the current wholesale price for energy in the U.K. and would add about £10 ($13) a year to electricity bills across the country.

The prospect of Hinkley Point C being shelved has led observers to explore renewables as an alternative. The nuclear power plant was scheduled to deliver 7 percent of the U.K.’s energy needs and help the country meet its carbon reduction targets.

Following the approval's reversal last month, several sources have noted that solar and wind power are on course to deliver energy at much lower cost than nuclear by the time Hinkley Point C is scheduled to come on-line in 2025.

Some are advocating concentrating solar power, or solar thermal, as a way to help fill the gap.

London-based Nur Energie already has a project, called TuNur, that is semi-permitted, with an interconnection point in Italy and the potential to start construction in 2018 and deliver power by 2020.

“An indicative power-purchase agreement has been agreed with one of the big six U.K. utilities for the purchase and distribution of the first 500 megawatts of capacity from the project,” said Kevin Sara, Nur Energie CEO.

“Several investment funds are ready to step in if the U.K. government offers a suitable contract for difference. We have worked with Imperial College and other expert consultants who have confirmed that sufficient transmission capacity is in place to move the power.”

Sara said the risk of bringing solar energy from Tunisia, where the project is planned, is roughly the same as importing gas from Algeria, which already forms part of the U.K. energy mix, and no more volatile than relying on Russian gas or uranium supplies from Niger.

“We are targeting a landed price that would be competitive against offshore wind and new nuclear,” said Sara.

“TuNur will deliver dispatchable power ensuring delivery only at times of high demand and thus highest market price, thus minimizing the total subsidy cost to the U.K. and differentiating it from offshore wind and new nuclear.”

The U.K. government’s own estimates are that the cost of onshore wind and large-scale solar will have dropped to between £50 and £75 ($66 and $99) per megawatt-hour by the middle of the next decade.

And according to a report by the Energy & Climate Intelligence Unit, a nonprofit organization, “replacing all Hinkley electricity with additional offshore wind farms would cut the average household bill by £10 to £20 per year.”

The problem, according to ERP, is that replacing nuclear with offshore wind would require a prohibitive amount of energystorage

“In a report published last year, ERP demonstrated that it is essential to develop new firm low-carbon capacity to meet the de-carbonization targets,” said Andy Boston, head of the analysis team at the firm. “The work demonstrated that without this, variable renewables like wind and PV would need an unfeasibly large amount of long-term storage to effectively utilize their output to displace unabated fossil [fuel].”

The study found 80 percent of U.K. of electricity could in theory be de-carbonized with about 70 gigawatts each of wind and PV, but this would require 1.5 terawatt-hours a year of storage, which is about 50 times the current pumped storage capability in the country.

“The role of electricity storage is never likely to be one of firming up renewables to the point where they can be considered baseload,” predicted Boston.

In its analysis, ERP said new nuclear is needed because government support is lacking for two other low-carbon base-load capacity contenders -- biomass and fossil fuel with carbon capture and storage.

The study did not consider bringing in concentrated solar power, with thermal storage, from north Africa. However, “CSP would fall into the same category as firm low-carbon supply, so yes, it would count,” said the organization.